The present invention relates to a milling cutter body for chip-breaking machining.
A typical milling tool comprises a milling cutter body which is fastenable at the end of a rotating shaft in a predetermined relation to its rotational axis, and a plurality of cutting edges being carried at an outer periphery of the milling cutter body at a radial distance from the rotational axis, so that the cutting edges describe a circle around the central rotational axis of the shaft when the cutter body is rotated by the shaft. All parts of the milling cutter body are disposed axially and radially behind the cutting edges, so that these edges may unobstructedly come into contact with and machine the surface of a workpiece that is held by the machine in which the shaft rotates. Since the cutting edges are short, they perform a relatively narrow cutting, wherefore the tool is used with a transversal feed, i.e., the direction of feed is parallel to the machined surface of the workpiece.
In relation with milling cutters with mechanically fastened cutting inserts, it has turned out to be difficult to fasten the inserts with the required precision for obtaining a fine smooth surface on the workpiece and a long tool-life. In order to attain the required surface smoothness it is necessary that the cutting edges attain a possibly exact position, both radially and axially. Moreover, an exact positioning of the so called parallel land angle is very important for the fineness and smoothness of the produced surface. The "parallel land angle" is the angle between the operative cutting edge and the produced surface of the workpiece. This angle should be as small as possible; in other words, it should preferably be zero. However, it has proved to be very difficult to attain this, especially for all cutting edges of the cutter body.
Thus, a first object of the present invention is to provide a milling cutter body comprising cutting edges, whose parallel land angles can be finely adjusted with the highest possible precision.
A second object of the present invention is to make possible said fine adjustment of the parallel land angle at the same time as there is a possibility of finely adjusting the axial position of the cutting edges.
Another object of the present invention is to, when necessary, compensate for the inclination of the spindle of the machine.